What is an SSL Certificate?
An SSL (Secure Sockets Layer) Certificate is a computer file. This file is conceptually like an ID Card with a Key attached, issued by a Trusted Certifying Authority.
A Digital Certificate like this can be used to establish who you are, and by exchanging keys, to encrypt information sent between two parties.
Where Certificates are Commonly Encountered
Digital Certificates are most commonly encountered day-to-day in the HTTPS protocol, which encrypts communication between Web Sites (Google Search, ASB Bank) and Web Browsers (Google Chrome, Microsoft Edge).
Encryption prevents sensitive information (like passwords or search terms) from being viewed by third parties, while being passed through different servers across the Internet.
The data transferred is only decrypted once it reaches its destination.
The encryption that protects the data is difficult to break.
Since 2015, there has been a push to increase the number of websites using HTTPS, and some sources suggest more than 50% of the Web is now using HTTPS[1]
Web Servers are assigned Certificates by the company that owns that web site (e.g. Google, Facebook)
SSL Certificates in the Browser
Modern Web Browsers show a different Address Bar if a website uses HTTPS instead of HTTP (a connection without encryption.)
HTTPS (Using SSL Certificate)
Figure 1: Address Bars for Secure Websites (HTTPS)
HTTP (no Certificate)
Figure 2: Address Bars for Insecure Websites (HTTP)
Please note:
Bing.com is now secure by default (forces HTTPS connections), much like Google.com
Certificate Requirements
You will need to work with SSL Certificates if you are implementing SSL Inspection.
For more information on SSL Inspection, see SSL Inspection
To download the certificate for SSL Inspection see the N4L SSL Inspection Certificate page
For a step-by-step guide to implementing SSL Inspection, see Web Filtering: Implementing SSL Inspection
References
Finley, K. (2017, June 03). Half the Web Is Now Encrypted. That Makes Everyone Safer. Retrieved August 12, 2017, from https://www.wired.com/2017/01/half-web-now-encrypted-makes-everyone-safer/
